With the issue of 2000-yen notes in recent years, banknote handling devices have been proposed that are able to accommodate in the same stacker banknotes of different length (for example 1000-yen notes, and 2000 yen notes which are longer than 1000-yen notes).
If banknotes of different length are to be accommodated in this way in the same banknote accommodating unit (stacker), there are the following problems.
These will be described with reference to a conventional banknote handling device 1 shown schematically in FIG. 13.
First of all, when a banknote A of long length is inserted into a banknote slot 2, this banknote A is carried by being gripped between an endless banknote conveyor belt 4 arranged on a banknote carrying path 3 of substantially U-shaped cross section and follower rollers 5 pressing against this belt. Then, if the banknote is identified as genuine by a banknote identification unit 6, carrying thereof is arrested at the time point where the rear edge A1 of this banknote A passes the banknote identification unit 6 and the banknote is temporarily retained (escrowed).
When a product is purchased, the temporarily retained (escrowed) banknote A of long length that has been inserted is accommodated in the stacker 14.
The banknote conveyor belt 4 is then again driven from the condition shown in FIG. 13 so that the banknote A is guided further downstream to the slit 9 of a stacker guide 8 that is arranged within the device body 7 of the banknote handling device 1.
After this, as shown in FIG. 14, when the rear edge A1 of the banknote A leaves the stacker roller 10, which is a final roller that presses against the banknote conveyor belt 4, this banknote A falls downwards of its own weight along the slit 9 until its tip A2 abuts the bottom face 7a of the device body 7, where it is stopped.
When the leading end A2 of the banknote A has been stopped in this way by abutment with the bottom face 7a of the device body 7, the rear edge A1 of the banknote A comes to rest in a position in which it does not cross the tip 12a of a banknote sagging preventing lever 12 that is freely rotatably journalled about a shaft 11 above the stacker roller 10 but whose rotation in the clockwise direction is restrained. It should be noted that the mounting position of the tip 12a of this banknote sagging preventing lever 12 is set beforehand in a position engaging the rear edge A1 when a banknote A of long length has fallen downwards and been stopped.
In this way, after the rear edge A1 of the banknote A has been stopped in a position in which it does not pass the tip 12a of the banknote sagging preventing lever 12, a lift table 13 as generally known comprising a link mechanism is reciprocated to left and right in the drawing as shown by the arrow F, whereupon the banknote A in the slit 9 of the stacker guide 8 is moved into the stacker 14 as shown in FIG. 15.
The banknote A that has been moved into this stacker 14 is constantly biased toward the stacker guide 8 by a pressure plate 16 biased in the leftwards direction in the drawing by pressing means comprising a coil spring 15.
At this point, the rear edge A1 of the banknote A is in a position engaging the tip 12a of the banknote sagging preventing lever 12, so even if the rear edge A1 of the banknote A is moved toward the slit 9 of the stacker guide 8 by swelling due to some cause such as swelling of the other accommodated banknotes accommodated in the stacker 14, this movement is inhibited by the banknote sagging preventing lever 12 that is engaged therewith and so does not reach the slit 9; consequently, there can be no interference between the banknote that is next guided into the slit 9 of the stacker 8 and the rear edge A1 of the banknote A accommodated in the stacker 14, so the banknote that is next to be accommodated moves smoothly into the stacker 14 and is stacked and accommodated therein.
In contrast, if, after a banknote B of shorter length than that of the banknote A described above has been escrowed, this banknote B falls down within the slit 9 of the stacker guide 8 of its own weight as shown in FIG. 16 and the tip B2 of the banknote B is stopped abutting the bottom face 7a of the device body 7 instead of being stopped midway and so may assume a position in which the rear edge B1 of the banknote B has passed the tip 12a of the banknote sagging preventing lever 12.
If this happens, if the lift table 13 is driven with this rear edge B1 of the banknote B still in a condition in which it has been stopped at a position past the tip 12a of the banknote sagging preventing lever 12, when the banknote B is accommodated in the stacker 14 as in FIG. 17, the rear edge B1 of the banknote B may project due to swelling within the slit 9 of the stacker guide 8 as in FIG. 18, resulting from some cause such as swelling of the other accommodated banknotes accommodated in the stacker 14; this may result in interference (collision) of the rear edge B1 of the banknote B with the next banknote to be guided into the slit 9, with a risk of causing the banknotes to jam at this point.
Conventionally, therefore, brake means was provided to inhibit the fall of banknotes to the lift table 13 in the vicinity of the stacker guide 8 so as to stop a banknote B of short length as described above in a position where it has not yet passed beyond the tip 12a of the banknote sagging preventing lever 12.
FIG. 19 is a schematic cross-sectional view of a banknote handling device 21 wherein brake means 20 is provided as described above; parts that are identical with those of FIGS. 14 to 18 are shown with the same reference symbols.
As shown in FIG. 20, which is an enlarged perspective view of its main portion, this brake means 20 comprises a projection 22 that projects at the side of the lift table 13. Such a projection 22 is also provided in a symmetrical position along the width direction of the lift table 13.
This projection 22 comprises an inclined section 22a that guides the banknote and a parallel face 22b parallel with the slit 9 of the stacker guide 8, this parallel face 22b projecting in a direction such as to block the width of the slit 9.
With such brake means 20, when for example a banknote B falls down along the slit 9 of the stacker guide 8 as shown by the arrow G as in FIG. 21, first of all its tip B2 is guided along the inclined face 22a of the projection 22 toward the parallel face 22b. 
Thus, when the tip B2 of a banknote B is guided toward the parallel face 22b, as shown in FIG. 22, the side B3 of the banknote B is simultaneously curved by the parallel face 22b so that the side B3 of the banknote B and the upper edge 9a of the slit 9 are in pressure contact due to the resilient force of the banknote produced by the curved section B4, with the result that frictional force acting as brake force F acts in this interval.
By the action of the brake force F produced by the frictional force of this projection 22, when the banknote B falls down in the direction of the arrow G and is carried, the tip B2 of this banknote B does not reach the bottom face 7a of the device body 7 shown in FIG. 23, so the banknote B in question is stopped midway and the rear edge B1 of the banknote B is therefore stopped in a position that does not pass the tip 12a of the banknote sagging preventing lever 12.
Consequently, the rear edge B1 of the banknote B stops in a position in which it has not passed the tip 12a of the banknote sagging preventing lever 12, so there is no possibility of the rear edge B1 of the banknote B projecting as shown in FIG. 18 due to swelling in the slit 9 of the stacker guide 8 due to some cause such as the swelling of the other accommodated banknotes accommodated in the stacker 14, so interference (collision) of the rear edge B1 of the banknote B with the next banknote B guided within the slit 9 does not occur and there is no risk of the banknotes becoming jammed at this point.
However, since, as shown in FIG. 20, the brake means 20 of the conventional banknote handling device 21 described above is constituted by a projection 22 comprising a parallel face 22b and an inclined part 22a projecting at the side of the lift table 13 and, as shown in FIG. 22, the radius of curvature of the curved part B4 of the banknote is unchanged even if the tip of the banknote is carried downstream of the parallel face 22b, the construction is one in which the resilient force applied to the upper edge 9a of the slit 9 by this curved part B4 does not change and the frictional contact surface area of the banknote side face B3 and the upper edge 9a of the slit 9 gradually increases as the banknote as a whole moves downstream of the slit 9.
The relationship between the distance moved by the banknote tip B2 along the parallel face 22b and the brake force F applied to the banknote tip B2 is therefore as shown graphically in FIG. 24. The brake force F applied to the banknote tip B2 therefore remains large without changing, even if the banknote tip B2 moves downstream of the parallel face 22b; the result of this is therefore that there is an abrupt increase in the braking force acting on the banknote as a whole as the banknote moves downstream of the slit 9.
Consequently, when the tip A2 of a banknote A of long length is guided downstream of the slit 9, being guided by the parallel face 22b of this projection 22, an abruptly increasing brake force acts on the banknote as a whole, causing the fall (movement) of the banknote A to be stopped midway and furthermore giving rise to the risk, as shown in FIG. 25, of a paper jam D occurring within the slit 9 of the stacker guide 8 due to the carrying force of the stacker roller 10, which is the last roller pressing on the banknote conveyor belt 4. This tendency is even more marked when guiding banknotes A of long length that are formed with creases.
Also, since the projection 22 described above is moved to left and right by the link mechanism and therefore projects at the side of the lift table 13, where there may be large errors of positional location, there is a risk of generation of errors of positional location due to large differences in relative position of the projection 22 with respect to the slit 9 of the stacker guide 8 fixed to the device body 7 occurring with each back and forth movement of the lift table 13. If this results in the relative position of the lift table 13 and the slit 9 becoming different, there may be a large change in the radius of curvature of the curved part of the banknote produced by the projection 22, resulting in large variation of the frictional force acting between the side of the banknote and the upper edge 9a of the slit 9; there is therefore a risk that it may not be possible to stop the banknote always in a fixed position irrespective of banknote length, because of changes in the brake force on the banknote produced by the projection 22.
In view of the above, an object of the present invention is to provide a banknote handling device in which jamming of banknotes cannot occur and which is capable of locating a banknote in position and stopping the banknote as far as possible in a fixed position.